1. Field of the Invention
The present invention relates to an inkjet recording apparatus, and in particular to a recording apparatus used as an output device, such as an ink-jet recording apparatus that conducts recording by discharging ink droplets onto a recording medium, and a fax machine, a copier, a printer composite device and a workstation disposed with such a function.
2. Description of the Related Art
Among inkjet recording apparatuses that record an image by discharging ink droplets onto a recording medium such as paper, there is a so-called scanning format inkjet recording apparatus where an inkjet recording head is disposed in a moving member such as a carriage and moving of the inkjet recording head in the direction orthogonal to the recording medium conveyance direction (main scanning) and moving of the recording medium (sub-scanning) are alternately conducted.
In this scanning format inkjet recording apparatus, the manufacturing yield of the inkjet recording head is high because the inkjet recording head is compact (as the requisite minimum configuration, it suffices if there is one nozzle for one recording head).
However, a limit has arisen in the pursuit of high productivity (conducting image recording on many recording media per unit time) because reciprocal movement (main scanning) of the inkjet recording head is indispensable at the time of image recording.
In order to realize high productivity, a so-called full line head format inkjet recording apparatus has been proposed where a long inkjet recording head, which can conduct image recording across a region that is about the same as the width of the recording medium or larger, is fixed and image recording is conducted on the recording medium by conveying only the recording medium. With this format, high productivity can be achieved in comparison to the scanning format because reciprocal movement of the inkjet recording head is not necessary.
For example, Japanese Patent Application Laid-Open Publication (JP-A) No. 5-104705 discloses a recording apparatus disposed with full multi ink-jet recording heads that can simultaneously conduct recording across the entire width of the recording paper. Similarly, JP-A No. 6-126943 discloses an ink-jet recording apparatus disposed with a so-called full line type inkjet recording head.
Examples of specific configurations of such long inkjet recording heads include a configuration where, as described in JP-A No. 8-132700 for example, the length is satisfied by a combination of plural recording heads and a configuration where one recording head is integrally formed. However, advanced microfabrication technology is required in order to configure a long inkjet recording head with one member. In other words, because heads including several thousands to several tens of thousands of nozzles must be manufactured as an integral part, sometimes the yield becomes poor.
The length of the recording head can be increased by joining together unit heads of a short length in the width direction of the recording medium, as described in JP-A No. 7-251505, JP-A No. 7-186386, JP-A No. 10-95113, JP-A No. 2001-293871, JP-A No. 2001-301199, JP-A No. 2002-103598 and JP-A No. 2002-59559, for example.
However, with this configuration, it becomes necessary to integrally replace the long recording head even when a drawback such as nozzle clogging arises in a specific unit head, so that costs necessary for the replacement become extremely high.